n=int(input())
s=input()
m=n//2
if s=='('*m+')'*m:
  a=2
else:
  a=1
M=998244353
N=10**6
F=[1]
for i in range(N):F+=F[i]*(i+1)%M,
c=lambda l,k:F[l]*pow(F[k]*F[l-k],M-2,M)
ans=0
for i in range(m+1):
  ans+=c(m,i)**a
  ans%=M
print(ans)